Children can still get hurt if they collide with other kids, hit the trampoline frame, or land awkwardly, Glatter pointed out.

According to the trampoline parks association, the typical trampoline park is up to 40,000 square feet, and holds various trampoline "courts." Each court contains any number of trampoline "beds" that are connected to each other to form one large surface that's enclosed with padded side walls, or sometimes angled trampolines.

The fact that kids get hurt using trampolines is nothing new. Home trampolines have long been recognized as a potential hazard, and the American Academy of Pediatrics advises parents against buying them.

Those home versions are still the most common cause of trampoline injuries, the new study found.

But, Kasmire said, there was no increase in ER visits due to home trampolines. The upward trend was confined to injuries sustained at parks.

Dr. Barbara Pena is research director of the emergency department at Nicklaus Children's Hospital in Miami. She was not surprised by the increase in park injuries, because she's seen the trend firsthand.

"We've always seen trampoline injuries," Pena said. "But now we're seeing more and more of them happening at the parks."

The findings are based on records from a nationally representative sample of 100 hospital emergency rooms. Between 2010 and 2014, the hospitals saw almost 92,000 trampoline-related injuries (from homes and parks) each year, on average.

In 2014, nearly 7,000 people landed in the ER after a trampoline park mishap.

Boys, average age 13, were hurt more often than girls. And younger children were more likely than teenagers or adults to sustain a bone break; fractures accounted for nearly half of injuries among children younger than 6, for example.

Young children can be at particular risk if older, larger kids are jumping nearby, Glatter pointed out. "That's a recipe for disaster," he said.

Pena agreed. "There should absolutely be a division of age groups at these parks," she said.

If parents want to take the family to a trampoline park, Kasmire had some advice: Supervise your kids the whole time, forbid flipping or any other "stunts," and be wary if the trampoline area is crowded.

Glatter suggested having kids wear the same type of protective gear they would when biking or skateboarding.

While children and teenagers accounted for most park injuries, there were also adult patients.

And it's teens and adults who are most prone to trying stunts, Kasmire said. She had advice for them, too: "Don't try to do things that are beyond your skill level."

The study results were published online Aug. 1 in the journal Pediatrics.

More information

The American Academy of Pediatrics has recommendations on trampoline use.